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Diffstat (limited to 'theories7/Sets/Powerset_facts.v')
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diff --git a/theories7/Sets/Powerset_facts.v b/theories7/Sets/Powerset_facts.v new file mode 100755 index 00000000..fbe7d93e --- /dev/null +++ b/theories7/Sets/Powerset_facts.v @@ -0,0 +1,276 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) +(****************************************************************************) +(* *) +(* Naive Set Theory in Coq *) +(* *) +(* INRIA INRIA *) +(* Rocquencourt Sophia-Antipolis *) +(* *) +(* Coq V6.1 *) +(* *) +(* Gilles Kahn *) +(* Gerard Huet *) +(* *) +(* *) +(* *) +(* Acknowledgments: This work was started in July 1993 by F. Prost. Thanks *) +(* to the Newton Institute for providing an exceptional work environment *) +(* in Summer 1995. Several developments by E. Ledinot were an inspiration. *) +(****************************************************************************) + +(*i $Id: Powerset_facts.v,v 1.1.2.1 2004/07/16 19:31:39 herbelin Exp $ i*) + +Require Export Ensembles. +Require Export Constructive_sets. +Require Export Relations_1. +Require Export Relations_1_facts. +Require Export Partial_Order. +Require Export Cpo. +Require Export Powerset. + +Section Sets_as_an_algebra. +Variable U: Type. +Hints Unfold not. + +Theorem Empty_set_zero : + (X: (Ensemble U)) (Union U (Empty_set U) X) == X. +Proof. +Auto 6 with sets. +Qed. +Hints Resolve Empty_set_zero. + +Theorem Empty_set_zero' : + (x: U) (Add U (Empty_set U) x) == (Singleton U x). +Proof. +Unfold 1 Add; Auto with sets. +Qed. +Hints Resolve Empty_set_zero'. + +Lemma less_than_empty : + (X: (Ensemble U)) (Included U X (Empty_set U)) -> X == (Empty_set U). +Proof. +Auto with sets. +Qed. +Hints Resolve less_than_empty. + +Theorem Union_commutative : + (A,B: (Ensemble U)) (Union U A B) == (Union U B A). +Proof. +Auto with sets. +Qed. + +Theorem Union_associative : + (A, B, C: (Ensemble U)) + (Union U (Union U A B) C) == (Union U A (Union U B C)). +Proof. +Auto 9 with sets. +Qed. +Hints Resolve Union_associative. + +Theorem Union_idempotent : (A: (Ensemble U)) (Union U A A) == A. +Proof. +Auto 7 with sets. +Qed. + +Lemma Union_absorbs : + (A, B: (Ensemble U)) (Included U B A) -> (Union U A B) == A. +Proof. +Auto 7 with sets. +Qed. + +Theorem Couple_as_union: + (x, y: U) (Union U (Singleton U x) (Singleton U y)) == (Couple U x y). +Proof. +Intros x y; Apply Extensionality_Ensembles; Split; Red. +Intros x0 H'; Elim H'; (Intros x1 H'0; Elim H'0; Auto with sets). +Intros x0 H'; Elim H'; Auto with sets. +Qed. + +Theorem Triple_as_union : + (x, y, z: U) + (Union U (Union U (Singleton U x) (Singleton U y)) (Singleton U z)) == + (Triple U x y z). +Proof. +Intros x y z; Apply Extensionality_Ensembles; Split; Red. +Intros x0 H'; Elim H'. +Intros x1 H'0; Elim H'0; (Intros x2 H'1; Elim H'1; Auto with sets). +Intros x1 H'0; Elim H'0; Auto with sets. +Intros x0 H'; Elim H'; Auto with sets. +Qed. + +Theorem Triple_as_Couple : (x, y: U) (Couple U x y) == (Triple U x x y). +Proof. +Intros x y. +Rewrite <- (Couple_as_union x y). +Rewrite <- (Union_idempotent (Singleton U x)). +Apply Triple_as_union. +Qed. + +Theorem Triple_as_Couple_Singleton : + (x, y, z: U) (Triple U x y z) == (Union U (Couple U x y) (Singleton U z)). +Proof. +Intros x y z. +Rewrite <- (Triple_as_union x y z). +Rewrite <- (Couple_as_union x y); Auto with sets. +Qed. + +Theorem Intersection_commutative : + (A,B: (Ensemble U)) (Intersection U A B) == (Intersection U B A). +Proof. +Intros A B. +Apply Extensionality_Ensembles. +Split; Red; Intros x H'; Elim H'; Auto with sets. +Qed. + +Theorem Distributivity : + (A, B, C: (Ensemble U)) + (Intersection U A (Union U B C)) == + (Union U (Intersection U A B) (Intersection U A C)). +Proof. +Intros A B C. +Apply Extensionality_Ensembles. +Split; Red; Intros x H'. +Elim H'. +Intros x0 H'0 H'1; Generalize H'0. +Elim H'1; Auto with sets. +Elim H'; Intros x0 H'0; Elim H'0; Auto with sets. +Qed. + +Theorem Distributivity' : + (A, B, C: (Ensemble U)) + (Union U A (Intersection U B C)) == + (Intersection U (Union U A B) (Union U A C)). +Proof. +Intros A B C. +Apply Extensionality_Ensembles. +Split; Red; Intros x H'. +Elim H'; Auto with sets. +Intros x0 H'0; Elim H'0; Auto with sets. +Elim H'. +Intros x0 H'0; Elim H'0; Auto with sets. +Intros x1 H'1 H'2; Try Exact H'2. +Generalize H'1. +Elim H'2; Auto with sets. +Qed. + +Theorem Union_add : + (A, B: (Ensemble U)) (x: U) + (Add U (Union U A B) x) == (Union U A (Add U B x)). +Proof. +Unfold Add; Auto with sets. +Qed. +Hints Resolve Union_add. + +Theorem Non_disjoint_union : + (X: (Ensemble U)) (x: U) (In U X x) -> (Add U X x) == X. +Intros X x H'; Unfold Add. +Apply Extensionality_Ensembles; Red. +Split; Red; Auto with sets. +Intros x0 H'0; Elim H'0; Auto with sets. +Intros t H'1; Elim H'1; Auto with sets. +Qed. + +Theorem Non_disjoint_union' : + (X: (Ensemble U)) (x: U) ~ (In U X x) -> (Subtract U X x) == X. +Proof. +Intros X x H'; Unfold Subtract. +Apply Extensionality_Ensembles. +Split; Red; Auto with sets. +Intros x0 H'0; Elim H'0; Auto with sets. +Intros x0 H'0; Apply Setminus_intro; Auto with sets. +Red; Intro H'1; Elim H'1. +LApply (Singleton_inv U x x0); Auto with sets. +Intro H'4; Apply H'; Rewrite H'4; Auto with sets. +Qed. + +Lemma singlx : (x, y: U) (In U (Add U (Empty_set U) x) y) -> x == y. +Proof. +Intro x; Rewrite (Empty_set_zero' x); Auto with sets. +Qed. +Hints Resolve singlx. + +Lemma incl_add : + (A, B: (Ensemble U)) (x: U) (Included U A B) -> + (Included U (Add U A x) (Add U B x)). +Proof. +Intros A B x H'; Red; Auto with sets. +Intros x0 H'0. +LApply (Add_inv U A x x0); Auto with sets. +Intro H'1; Elim H'1; + [Intro H'2; Clear H'1 | Intro H'2; Rewrite <- H'2; Clear H'1]; Auto with sets. +Qed. +Hints Resolve incl_add. + +Lemma incl_add_x : + (A, B: (Ensemble U)) + (x: U) ~ (In U A x) -> (Included U (Add U A x) (Add U B x)) -> + (Included U A B). +Proof. +Unfold Included. +Intros A B x H' H'0 x0 H'1. +LApply (H'0 x0); Auto with sets. +Intro H'2; LApply (Add_inv U B x x0); Auto with sets. +Intro H'3; Elim H'3; + [Intro H'4; Try Exact H'4; Clear H'3 | Intro H'4; Clear H'3]. +Absurd (In U A x0); Auto with sets. +Rewrite <- H'4; Auto with sets. +Qed. + +Lemma Add_commutative : + (A: (Ensemble U)) (x, y: U) (Add U (Add U A x) y) == (Add U (Add U A y) x). +Proof. +Intros A x y. +Unfold Add. +Rewrite (Union_associative A (Singleton U x) (Singleton U y)). +Rewrite (Union_commutative (Singleton U x) (Singleton U y)). +Rewrite <- (Union_associative A (Singleton U y) (Singleton U x)); Auto with sets. +Qed. + +Lemma Add_commutative' : + (A: (Ensemble U)) (x, y, z: U) + (Add U (Add U (Add U A x) y) z) == (Add U (Add U (Add U A z) x) y). +Proof. +Intros A x y z. +Rewrite (Add_commutative (Add U A x) y z). +Rewrite (Add_commutative A x z); Auto with sets. +Qed. + +Lemma Add_distributes : + (A, B: (Ensemble U)) (x, y: U) (Included U B A) -> + (Add U (Add U A x) y) == (Union U (Add U A x) (Add U B y)). +Proof. +Intros A B x y H'; Try Assumption. +Rewrite <- (Union_add (Add U A x) B y). +Unfold 4 Add. +Rewrite (Union_commutative A (Singleton U x)). +Rewrite Union_associative. +Rewrite (Union_absorbs A B H'). +Rewrite (Union_commutative (Singleton U x) A). +Auto with sets. +Qed. + +Lemma setcover_intro : + (U: Type) + (A: (Ensemble U)) + (x, y: (Ensemble U)) + (Strict_Included U x y) -> + ~ (EXT z | (Strict_Included U x z) + /\ (Strict_Included U z y)) -> + (covers (Ensemble U) (Power_set_PO U A) y x). +Proof. +Intros; Apply Definition_of_covers; Auto with sets. +Qed. +Hints Resolve setcover_intro. + +End Sets_as_an_algebra. + +Hints Resolve Empty_set_zero Empty_set_zero' Union_associative Union_add + singlx incl_add : sets v62. + + |